U.S. Pat. No. 4,367,370, owned by the assignee of this application, discloses a wall system formed from a plurality of series-connected electrically prewired panels, and more specifically to a wall system wherein power-taps such as for light fixtures and conventional electrical receptacles can be selectively positioned on the panels and selectively switchably connected, at their point of use, to any one of a plurality of different electrical circuits. The wall system of the aforesaid patent is provided with three different electrical circuits extending therealong, and the switchable power tap is removably connected to a power block or terminal associated with the respective panel, and for this purpose a plug-in connection is provided therebetween. The power tap is provided with five conductive prongs which project into the power block for connection to the three different electrical circuits associated therewith. The power tap, however, has internal switching structure such that only one of three different prongs is connected to the output of the power tap, such as a conventional receptacle, whereby the output is hence selectively connected to only one of the three different circuits. The switching structure permits switching and hence selection between the three different circuits only when the power tap is disconnected from the power block.
The electrified wall system of the aforesaid patent, and specifically the switchable power tap associated therewith, has proven highly desirable in its ability to permit a circuit-selecting function to be performed at each individual point of use merely by manually displacing the switch associated with the respective power tap so as to permit selection of the desired circuit, following which the power tap is then plugged into its respective power block. However, in a continuing effort to improve upon the design, simplicity, function and reliability of the switchable power tap, specifically when same comprises a receptacle unit, the improved switchable power tap of this invention has hence been developed.
More specifically, this invention relates to an improved switchable power tap, specifically a receptacle unit, which is removably connectable to a power block or terminal associated with an electrically prewired wall system defined by interconnected panels, which improved power tap permits the output (that is, the receptacle) thereof to be individually selected at its point of use so as to be electrically connected to any selected one of the several electrical circuits which extend along the prewired wall panels. The improved switchable power tap of this invention permits the switching function to occur only when the power tap is electrically disconnected, and hence physically disconnected, from its respective power block. However, with this improved switchable power tap, the input to the power tap is electrically connected to only a single circuit, rather than to a plurality of circuits as with the power tap of the aforesaid patent, so that the improved power tap of this invention is in its entirety of a single electrical phase.
In addition, the improved switchable power tap of this invention is believed to provide a more reliable and more efficient switch due to its providing a more intimate electrical contact, and is believed to be less sensitive to the accuracy of the switching position. This improved power tap is also structurally simpler and less costly to manufacture.
In the improved power tap of this invention, there is provided a housing mounting therein three electrically conductive members or plates. These three plates define the electrical outlet portion of the power tap, which outlet portion in the preferred embodiment comprises a conventional electrical receptacle. The power tap also includes an electrical inlet portion which is defined by three electrically conductive prongs adapted to create a plug-like engagement with a power block. Two of the prongs are permanently electrically connected to two of the conductive plates. The third prong is part of a switch structure and is slidably supported on but in continuous electrical engagement with a conductive guide member, the latter being electrically connected to the third conductive plate. This slidable, and hence switchable, prong can be selectively positioned in any one of several different positions, three in the disclosed embodiment, so that when the power tap is plugged into the power block, the switchable prong is hence electrically engaged with a selected one of the three different electrical circuits provided in the power block, depending upon the preselected position of the switchable prong.
Other objects and purposes of the invention will be apparent to persons familiar with systems of this type upon reading the following specification and inspecting the accompanying drawings.